During the campaign Cox has polled as high as 8 percent and as low as 1 percent, (some polls don’t even include his name), so it’s hard to peg his support. But any votes he receives on Nov. 6 could sway a too-close-to-call race – and help determine which party controls the U.S. Senate come January.

Whatever happens is fine with him, says Cox, who accuses both major party candidates of undermining the U.S. Constitution.

“The good news is no matter what happens in this election, either one or two of the unconstitutional candidates will be out of the Congress,” Cox says.

Rehberg, Tester and their supporters are projected to spend more than $20 million in a record-breaking Montana campaign. By contrast, the 36-year-old Cox has raised less than $5,000.

His signs appear almost nowhere in the state aside from at least one in the Bitterroot Valley featuring spray-painted letters on a white plywood board leftover from his 2010 run for state legislature.

The Libertarian message

Cox’s message seems simple: When it comes to the federal government, less is more. “Who out there is thinking to themselves, ‘If the government could just regulate me just a little bit more, I’d be happy’?” he asks. “I don’t think hardly anybody’s thinking like that.”

Cox is the only candidate who wants the U.S. to return to gold standard, and he supports a full audit of the Federal Reserve. He says more Americans could afford health care if there were fewer federal regulations and lower taxes.

He mistrusts both major parties. Democrats helped spend the nation into trillions of dollars of debt, he says, and Republicans aren’t the fiscal hawks they say they are.

“They’re going to swoop in and replace it with what, RomneyCare?” Cox said. “Well, if you’re against the government being involved in health care, why would you trust Republicans?”

For their part, Republicans have been skeptical of Cox and clearly worry that he could shave votes from Rehberg. A Rehberg mailer last featured photos of Rehberg and Libertarian-leaning Congressman Ron Paul over a message calling for an audit of the Federal Reserve.

Cox says earlier in the race he met with Rehberg campaign officials, who asked whether he was getting support from Tester.

“I did have one meeting with Rehberg’s campaign manager where he accused me of, I guess, getting my donations from the Jon Tester campaign, which was completely false,” Cox says.

Meanwhile, Tester’s campaign is working to play Cox’s presence in the race to their advantage. A week before the election, a Tester-friendly group representing hunters and anglers ran a TV spot urging conservatives to vote for Cox instead of Rehberg.

What are the odds?

Experts suspect most Montana voters have made their choice. The number of undecided voters and die-hard Libertarians appears to be so small that University of Montana political scientist Jeff Greene calls them the “cookie crumb voters.”

“If (Cox) gets 3 or 4 percent, he will be doing extraordinarily well,” Greene says. “It could decide the election actually if that happens. If he were to get 3 or 4 percent, it would be most likely in my view to come off of Rehberg’s part.”

Because Libertarians tend to identify more closely with Republicans, votes for Cox would come from potential Rehberg voters, Greene says.

“And I would predict, if the Libertarians vote true to their heart, Tester would win the race,” Greene said. “But I don’t think they will.”

He says some conservatives who agree with Cox are likely to make a practical choice for Rehberg to help Republicans gain control of the U.S. Senate.